The invention relates to a telephone and particularly a mobile telephone that uses vibration instead of, or in addition to, an ordinary audible alarm to indicate a received call signal.
Usually, a telephone indicates a received call with an audible alarm, but in some cases and especially with mobile telephones the audible alarm may be disturbing. Then it is possible to use a vibrating alarm which means that the user who has the telephone in hand or in a pocket feels the vibration instead of hearing an audible alarm and is thus informed about a call.
There are a few known prior art telephones using a vibrating indicator. One such telephone is described in international patent application WO 93/15590, where a radio apparatus includes a means for receiving an information signal, a means for generating a silent alarm, a means for generating an audible alarm, and a means for activating a silent alarm for a first predetermined period and for activating an audible alarm for a second predetermined period on the basis of the received signal. The silent alarm is brought about by a vibrator which according to the drawing associated with the description is fixedly connected to the control part of the telephone and located beside the microphone/earpiece set.
As mentioned before, a silent alarm is desirable in some cases, but, in practice, most users will not need that function since it is always possible to turn the telephone off in solemn or important occasions in which silence is required. Therefore, a fixed vibrating alarm in a telephone increases the costs even if the user will not need one. This is a disadvantage, as telephones and particularly mobile telephones are becoming consumer products the base price of which should be kept as low as possible.